[5] Five years later in December 1966, Tunku Iskandar was appointed as the Raja Muda at the request of their father, Sultan Ismail and was approved by the Council of Royal Court, and placing him second in line to the royal throne behind Tunku Abdul Rahman.
[7] The decision took many people by surprise, including the then-Menteri Besar of Johor, Othman Saat who promptly criticised the Sultan's actions, and earning the wrath of Tunku Iskandar at the same time.
[4] Tunku Abdul Rahman, on the other hand, initially remained silent but later took his grievances to his press and expressed his shock and disappointment over his father's decision, suggesting that he had done nothing wrong in the twenty years as the Tunku Mahkota and also cited some of his significant contributions to the state during his tenure.
Tunku Abdul Rahman, by now in ailing health, held that post until his death in 1989.
[9] In his later years, his health, already plagued by diabetes, worsened, which ultimately saw one of his legs being amputated.